Abstract: In order to accurately obtain the natural ventilation pressure of the mine and understand its impact on the mine ventilation system and main fan, based on the real-time monitoring data of GD3(B) multi-parameter sensors, the air density of each point on the main ventilation line of the mine was calculated in real time on the basis of ideal gas state equation and Dalton's partial pressure law. The natural ventilation pressure of the mine was obtained by combining the elevation of each point, and the performance curve of the main fan was composited in real time. The results show that the natural ventilation pressure can be accurately calculated by the test data of the GD3(B) mine multi-parameter sensors. The change of surface air temperature has a great influence on the air temperature of the roadway on the inlet side of the mine, but a little influence on the air temperature of the roadway on the return side. The daily fluctuation of natural ventilation pressure of Nalinhe No.2 mine system is nearly 100 Pa. Through the coupling analysis of the measured natural ventilation pressure and the characteristic curve of mine main ventilator, the influence of natural ventilation pressure change on the ventilation condition of main ventilator can be accurately reflected.